* Replace pigz with zstd for backup compression This change replaces pigz (parallel gzip) with zstd (Zstandard) as the compression algorithm for mailcow backups while maintaining full backward compatibility with existing .tar.gz backups. Benefits: - Better compression ratios (12-37% improvement in tests) - Improved compression speed with modern algorithm - Maintains rsyncable functionality for incremental backups - Full backward compatibility for restoring old .tar.gz backups - Wide industry adoption and active development Changes: - Backup compression: pigz --rsyncable -p → zstd --rsyncable -T - Backup decompression: pigz -d -p → zstd -d -T - File extensions: .tar.gz → .tar.zst - Added get_archive_info() function for intelligent format detection - Updated backup Dockerfile to install zstd alongside pigz - Restore function now auto-detects and handles both formats - Updated FILE_SELECTION regex to recognize both .tar.zst and .tar.gz - Updated comments to reflect new file extension Backward Compatibility: - Restore automatically detects .tar.zst (preferred) or .tar.gz (legacy) - Existing .tar.gz backups can still be restored without issues - pigz remains installed in backup image for legacy support - Graceful fallback if backup file format not found Testing: - Added comprehensive test suite (test_backup_and_restore.sh) - 12 automated tests covering all scenarios: * Backup creation (both formats) * Restore (both formats) * Format detection and priority * Error handling (missing files, empty dirs) * Content integrity verification * Multi-threading configuration * Large file compression (8.59 MB realistic data) Test Results: ✓ zstd compression working ✓ pigz compression working (legacy) ✓ zstd decompression working ✓ pigz decompression working (backward compatible) ✓ Archive detection working ✓ Content integrity verified ✓ Format priority correct (.tar.zst preferred) ✓ Error handling for missing files ✓ Error handling for empty directories ✓ Multi-threading configuration verified ✓ Large file compression: 37.05% improvement ✓ Small file compression: 12.18% improvement * move testing script into development folder --------- Co-authored-by: DerLinkman <niklas.meyer@servercow.de>
mailcow: dockerized - 🐮 + 🐋 = 💕
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Misc
Important: mailcow makes use of various open-source software. Please assure you agree with their license before using mailcow. Any part of mailcow itself is released under GNU General Public License, Version 3.
mailcow is a registered word mark of The Infrastructure Company GmbH, Parkstr. 42, 47877 Willich, Germany.
The project is managed and maintained by The Infrastructure Company GmbH.
Originated from @andryyy (André)